Drivers prepare for their runs at the bus yard at 23rd and Indiana streets on in San Francisco on Wednesday, June 4, 2014. Most workers reported for work today and Muni should be operating at full capacity.

Drivers prepare for their runs at the bus yard at 23rd and Indiana streets on in San Francisco on Wednesday, June 4, 2014. Most workers reported for work today and Muni should be operating at full capacity.

Photo: Paul Chinn, The Chronicle

Drivers prepare for their runs at the bus yard at 23rd and Indiana... Photo-6405317.87255 - SFGate

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Bus drivers exchange a fist bump at the maintenance yard at 23rd and Indiana streets as more transit workers return to work on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, but the system is still not operating at full capacity. The union employees are upset by a contract proposal made by MTA management. less

Bus drivers exchange a fist bump at the maintenance yard at 23rd and Indiana streets as more transit workers return to work on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, ... more

Commuters ride an inbound Metro lightrail streetcar near the West Portal station on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, but the system is still not operating at full capacity. The union employees are upset by a contract proposal made by MTA management. less

Commuters ride an inbound Metro lightrail streetcar near the West Portal station on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for ... more

Muni passengers cross the street to the West Portal Metro station on the third day of a sickout by transit employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, but the system is still not operating at full capacity. The union employees are upset by a contract proposal made by MTA management. less

Muni passengers cross the street to the West Portal Metro station on the third day of a sickout by transit employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, ... more

Passengers ride an inbound Metro lightrail streetcar near the West Portal station on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, but the system is still not operating at full capacity. The union employees are upset by a contract proposal made by MTA management. less

Passengers ride an inbound Metro lightrail streetcar near the West Portal station on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for ... more

Commuters board a 38-Geary bus at 3rd Avenue and Geary Boulevard on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, but the system is still not operating at full capacity. The union employees are upset by a contract proposal made by MTA management. less

Commuters board a 38-Geary bus at 3rd Avenue and Geary Boulevard on the third day of a sickout by Muni employees in San Francisco, Calif. on Wednesday, June 4, 2014. More workers reported for work today, but ... more